The invention relates to a 
satellite post-compensation 
system based on the P2P technology, which is a 
satellite file transfer system for which such technologies as the 
network communication (
satellite network, Internet) technology, the Dot Net frame, the P2P technology, the file 
compensation algorithm, the 
data identification perfection, the addressing technology, etc. are utilized. The 
satellite network is utilized as a 
trunk transmission network to transmit the large-scale 
mass file data. By combining the advanced Dot Net frame and the P2P technology over 
the Internet, the defect calculation analysis and the compensation are applied to the file received through the satellite transmission so as to ensure that the unreliable satellite unidirectional 
file transfer is changed into the reliable integral 
file transfer. The traditional compensation solution is divided into the pre-compensation and the post-compensation. The pre-compensation means that a certain proportion of data is repeatedly transmitted through the 
satellite network, however, the pre-compensation reduces the efficiency of the satellite communication. In the post-compensation, the requirement for ground 
data transmission can be met only by establishing a large amount of 
data node servers, which cause the cost of the entire 
system to be excessively high. The invention breaks through 
the Internet transmission restriction applied to the traditional post-compensation and reduces the number of the ground 
data node servers so as to greatly lower the system cost and enhance the compensation speed of the ground network and the utilization ratio of the network resources, and constructs an effective post-compensation system for satellite file transfer with a lower cost.